Further refactor is_wheel_from_cache

src/pip/_internal/req/req_install.py

@@ -109,11 +109,9 @@ def __init__(
             link = Link(req.url)
         self.link = self.original_link = link
 
-        # When is_wheel_from_cache is True, it means that this InstallRequirement
-        # is a local wheel file in the cache of locally built wheels.
-        self.is_wheel_from_cache = False
-        # When is_wheel_from_cache is True, this is the source link corresponding
-        # to the cache entry, which was used to download and build the cached wheel.
+        # When this InstallRequirement is a wheel obtained from the cache of locally
+        # built wheels, this is the source link corresponding to the cache entry, which
+        # was used to download and build the cached wheel.
         self.cached_wheel_source_link: Optional[Link] = None
 
         # Information about the location of the artifact that was downloaded . This
@@ -443,6 +441,12 @@ def is_wheel(self) -> bool:
             return False
         return self.link.is_wheel
 
+    @property
+    def is_wheel_from_cache(self) -> bool:
+        # When True, it means that this InstallRequirement is a local wheel file in the
+        # cache of locally built wheels.
+        return self.cached_wheel_source_link is not None
+
     # Things valid for sdists
     @property
     def unpacked_source_directory(self) -> str:

src/pip/_internal/resolution/legacy/resolver.py

@@ -432,7 +432,6 @@ def _populate_link(self, req: InstallRequirement) -> None:
             logger.debug("Using cached wheel link: %s", cache_entry.link)
             if req.link is req.original_link and cache_entry.persistent:
                 req.cached_wheel_source_link = req.link
-                req.is_wheel_from_cache = True
             if cache_entry.origin is not None:
                 req.download_info = cache_entry.origin
             else:

src/pip/_internal/resolution/resolvelib/candidates.py

@@ -281,7 +281,6 @@ def __init__(
             assert ireq.link.is_file
             if cache_entry.persistent and template.link is template.original_link:
                 ireq.cached_wheel_source_link = source_link
-                ireq.is_wheel_from_cache = True
             if cache_entry.origin is not None:
                 ireq.download_info = cache_entry.origin
             else: